If you use Internet Explorer, you might want to switch to another browser for a little while. On Saturday, Microsoft posted an advisory about a new security vulnerability affecting Internet Explorer 6... and 7, 8, 9, 10, and 11. All recent versions of the browser are affected, and a fix is still pending.
Here's how Microsoft describes the problem:
The vulnerability is a remote code execution vulnerability. The vulnerability exists in the way that Internet Explorer accesses an object in memory that has been deleted or has not been properly allocated. The vulnerability may corrupt memory in a way that could allow an attacker to execute arbitrary code in the context of the current user within Internet Explorer. An attacker could host a specially crafted website that is designed to exploit this vulnerability through Internet Explorer and then convince a user to view the website.
This isn't just a hypothetical, mind you. The company says it's "aware of limited, targeted attacks" that try to exploit the vulnerability. CNet News reports those attacks are targeting "financial and defense organization in the US."
Now, Microsoft seems to suggest that such attacks involve links in e-mails and instant messages, and "an attacker would have no way to force users to visit these websites." Nevertheless, by successfully exploiting the vulnerability, an attacker "could gain the same user rights as the current user."
So, where's the fix? Microsoft says it's still investigating the issue, and it will "take the appropriate action" once the investigation is over. That action "may include providing a solution through our monthly security update release process, or an out-of-cycle security update, depending on customer needs." No update has been released just yet, though.